5.1 Hazchem guidance

5.1 Guidance on local arrangements for hazardous chemicals

This guidance is primarily to help heads of department identify:

• The level of risk arising from hazardous chemicals in their area, and
• The standard of risk control system that they need to have in place.

The purpose of the risk control system is to ensure that risks arising from hazardous chemicals are eliminated or effectively controlled. The scale of the risk control system will depend on the extent to which chemicals are used or generated, the number of people involved, and the hazardous nature of the chemicals.

The risk control system needs to be an integral part of the process by which the work of the department or area is carried out. It needs to address initiation of activities, purchasing and acceptance of materials, disposal of waste, handling, storage and use.

The following process will help you develop your risk control system.

1 Find out about the range of chemicals that are or can be stored, used, or generated in your department.

2 Check out the hazard classification of these chemicals. Hazard classification is dealt with in the section on 'Chemical hazard classification'.

3 Rank the level of risk arising from chemicals for your department using the 'Guidance on risk control systems' table. Note from the table the sort of arrangements (risk control system) you are likely to need.

4 Define who carries out assessments. Do they have appropriate skills and competence for the hazard characteristics of the substances they are assessing?

5 Obtain a baseline of the specific risks and appropriate precautions for your department by having the most common activities and activities involving the most hazardous chemicals assessed.

6 Based on the findings of the risk assessments:

• Develop a basic set of precautions for handling and use of chemicals in the department. These precautions should include arrangements for dealing with spillages and disposal and should apply to all chemicals whether purchased or accepted as samples free of charge.
• Define who has freedom to initiate work involving use or generation of chemicals.
• Define who is authorised to purchase, or accept samples, of chemicals.
• Define how chemicals are to be received, distributed, and stored.
• Define where risk assessments are kept and by whom.
• Define who will maintain a register of the chemicals held by the faculty or department.
• Define how non-routine activities are to be assessed and controlled.
• Define where current material safety data sheets for all hazardous chemicals are kept and how they are maintained.
• Define who can work without supervision, and who has to be supervised and by whom.
• Define who need further training and instruction, and by whom: people need to be competent for the tasks they undertake.
• Define who arranges health surveillance with the Occupational Health Adviser for people who work with or are exposed to hazardous chemicals.

If your department is in the high or medium-high risk categories, you should specify

• Who organises necessary engineering controls such as local exhaust ventilation or flameproof electrics, and their regular testing, servicing, and maintenance;
• who checks whether exposure to chemical substances is within legal limits (e.g. occupational exposure limits).

7 Inform staff of these arrangements and encourage them to report any difficulties in the operation of these arrangements.

8 Monitor incidents and identify improvements to your arrangements.

9 Review the effectiveness of your arrangements.

Chemical hazard classification

The hazard characteristics of chemical substances are investigated and categorised by authoritative international bodies. This system results in chemicals being assigned 'risk phrases'. These 'risk phrases' can relate to health, reactivity, or environmental effects.

The University has developed a method for clarifying the type and severity of hazards. The system is similar to that described in 'COSHH Essentials', published by the HSE which deals specifically with health hazards.

The University's system involves allocating a hazard classification from 'A' to 'D' for the health, reactivity, and environmental hazards associated with the substance. The classification depends on the most serious risk phrase that has been allocated for the substance as set out in the following tables.

The dustiness or volatility of the substance is a major factor in how easy a substance is to contain, and hence to control. Substances are also classified according to their dustiness or volatility.

Health hazard classification:

Classification and description 

If risk phrases include:

D Serious irreversible health effects
R26, R27, R28, R39, R40, R41, R42, R45, R46, R48, R49, R60, R61, R62, R63, Sk

C Serious health effects
R23, R24, R25, R33, R35, R43, R67

B Harmful health effects
R20, R21, R22, R34, R36, R37, R38, R66

A Not classified as dangerous on basis of health effects

Reactivity hazard classification:

Classification and description

If risk phrases include:

D Extremely flammable or

Explosive or

Oxidising

R1, R4, R5, R6, R7, R12, R14, R15, R16, R17, R18, R19, R44

C Highly flammable
R11, R30

B Flammable
R10

A Not classified as dangerous on basis of physical effects

Environmental hazard classification:

Classification and description

If risk phrases include:

D Very toxic to organisms
R50

C Toxic to organisms, or

Dangerous to the ozone layer

R51, R54, R55, R56, R57

R59

B Harmful to organisms
R52, R53, R58

A Not classified as dangerous on basis of environmental effects

Classification of physical form:

• Dustiness or volatility
• Dustiness of solids
• Volatility of liquids

High

Fine, light powders that when used are form dust clouds that remain in the air for several minutes.
Use graph to determine volatility from the boiling point of the liquid and the maximum temperature to which it is exposed.

Medium

Crystalline, granular powders. When used, dust is seen but settles out quickly leaving dust on surfaces after use.

Low

Pellet-like solids that don't break up. Little dust is seen during use.

Guidance on risk control systems

• Risk level
• Hazards
• Guidance on risk control systems

High

Substances with serious (i.e hazard class 'D') hazard characteristics. Hazard class 'D' includes very toxic substances for which there are no safe limits (e.g carcinogens, skin and respiratory sensitisers), materials which are radioactive, or extremely flammable, or unstable, high energy substances, or not fully characterised but have the above characteristics.

• Highly volatile or dusty substances with hazard class 'C' i.e toxic or highly flammable or reactive materials.
• Substances of hazard class 'C' with multiple hazard characteristics.
• Substances with Maximum Exposure Limits.
• Mixing chemicals that can react violently.
• Carrying out reactions at elevated temperatures or pressures, or under vacuum.
• Risk control system needs to be robust.
• Monitoring of the effectiveness of the risk control system is essential
• Assessments and definition of appropriate precautions and contingency plans require technical knowledge and expertise, including knowledge of health & safety legislation and approved codes of practice.
• Engineering controls are likely to be required.
• Access to the chemicals or processes needs to be controlled.
• Health surveillance.
• Contingency plans are likely to be complex.

Medium high

Substances with hazard class 'C' e.g toxic or highly flammable or reactive materials that can be contained using standard controls.

• Substances with Occupational Exposure Standards.
• Mixing chemicals that react but not violently.
• Risk control system needs to be effective and appropriate for the scale of activity.
• Knowledge of relevant health & safety legislation and approved codes of practice is required for assessments and definition of appropriate precautions and contingency plans.
• Engineering controls are likely to be required.
• Access to the chemicals or processes needs to be restricted.
• Health surveillance.
• Contingency plans are necessary but straightforward.

Medium low

Substances with hazard class 'B'. Chemicals in this class are typically harmful, irritant, corrosive, or flammable.

• Mixing chemicals that do not react.
• Basic chemical risk control system with clearly defined arrangements, assessment resulting in clear precautions, people adequately trained, appropriate supervision and monitoring, with periodic reviews.
• Restrictions on access to chemicals or processes are advisable.
• The risk and safety phrases on the labels and material safety data sheets for each substance are likely to describe the appropriate precautions.

Low

Non-hazardous substances i.e low chemical reactivity, no adverse health or environmental effects, not flammable, nor explosive.

• People are aware of and follow basic rules for handling chemical substances including good housekeeping and personal hygiene.
• Checks are made to ensure that only non-hazardous substances are in use.